Ali Cheloee Darabi

• Research Associate at University of Stuttgart

Dual phase (DP) steels, which have an intricate microstructure, consist of ferrite and martensite phases and because of interaction between the ferrite and martensite phases, those have complex behaviors. In this study, the flow curves of two heat-treated DP steels, DP800 and DP980, were compared with those of the 2D and 3D micromechanical models b...

In this study, we quantitatively investigate the impact of 1.4 wt.% chromium and 1.4 wt.% molybdenum additions on pearlitic microstructure characteristics in 1 wt.% carbon steels. The study was carried out using a combination of experimental methods and phase field simulations. We utilized MatCalc v5.51 and JMatPro v12 to predict transformation beh...

This study aims to investigate the effect of chromium and molybdenum on the formation of pearlitic microstructure in 1% carbon steels. To obtain experimental data, 12mm wires of one benchmark (Fe-1C) and two trial alloys (Fe-1C-1.5Cr and Fe-1C 1.5Mo) are manufactured in-house by casting and hot caliber rolling. These wires are homogenized at a temp...

A comprehensive approach to understand the mechanical behavior of materials involves costly and time-consuming experiments. Recent advances in machine learning and in the field of computational material science could significantly reduce the need for experiments by enabling the prediction of a material’s mechanical behavior. In this paper, a reliab...

This study aimed to identify an optimal heat-treatment parameter set for an additively manufactured AlSi10Mg alloy in terms of increasing the hardness and eliminating the anisotropic microstructural characteristics of the alloy in as-built condition. Furthermore, the influence of these optimized parameters on the fatigue properties of the alloy was...

This study aims to identify an optimal heat-treatment parameter set for an additively manufactured AlSi10Mg alloy in terms of increasing the hardness and eliminating the anisotropic microstructural characteristics of the alloy in as-built condition. Furthermore, the influence of these optimized parameters on the fatigue properties of the alloy inve...

In this paper, the fracture behavior and micro-damage evolution in DP600 and DP980 steels were studied using experimental and numerical methods. First, four specimens with different loading conditions were tested to investigate the influence of the stress state on the fracture behavior and in-situ tensile tests were carried out in order to evaluate...

In this study, a micromechanical finite element model is proposed based on experimental data and the rule of the mixture (RoM) in order to predict the tensile behavior of mechanical properties of heat-treated dual-phase medical-grade titanium (Ti–6Al–4V). Tensile tests, micro-hardness measurements, and RoM were used to obtain flow curves for the α...

In this study, a micromechanical finite element model is proposed based on experimental data and the rule of the mixture (RoM) in order to predict the tensile behavior of mechanical properties of heat-treated dual-phase medical-grade titanium (Ti–6Al–4V). Tensile tests, micro-hardness measurements, and RoM were used to obtain flow curves for the α...

The effect of hydrogen on the microdamage evolution of 1200M advanced high-strength steel was evaluated by the combination of experimental and numerical approaches. In the experimental section, the tensile test was performed under different testing conditions, i.e., vacuum, in-situ hydrogen plasma charging (IHPC), ex-situ electrochemical hydrogen c...

Micromechanical behavior of two dual-phase steels is investigated using experimental and numerical methods. Experimental data for 2 dual phase steel specimens (SP1 and SP2) is obtained from the literature and is used to create 2D representative volume elements (RVEs) based on the continuum mechanics framework. Interphase of the specimens is incorpo...

A novel method to model the interphase between phases in DP steels is introduced and implemented on a specimen created from DP980. Use of the proposed method remedied the problem of underestimation of stress-strain curve by 2D RVEs and also showed that failure initiates at the interphase between phases.

A plate of dual phase steel was produced from low carbon steel with intercritical annealing treatment. Its optically determined surface microstructure was utilized to construct three different microstructural models. To describe the ductile damage in the ferritic matrix, the Gurson-Tvergaard-Needleman model was used with the failure in the martensi...

Since the advent of additive manufacturing techniques, regular porous biomaterials have emerged as promising candidates for tissue engineering scaffolds owing to their controllable pore architecture and feasibility in producing scaffolds from a variety of biomaterials. The architecture of scaffolds could be designed to achieve similar mechanical pr...

In this paper the macromechanical behavior of dual phase steel based on actual microstructure has been predicted. In order to prepare dual phase steelsc (DP) of different percent phase combinations, a low carbon steel (C-Mn) was subjected to intercritical annealing treatment (ICT) and quenched in water. Then, the actual microstructures of dual phas...

The stop-hole method is a simple and accessible crack arresting method widely used to retard and even to stop the fatigue crack propagation in structural components that cannot be replaced as soon as the crack is observed. It is commonly used to drill a hole at or near the crack tip to turn the crack into a notch, resulting in reduction of its stre...

Dual phase (DP) steels are among the advanced high strength steel (AHSS) products recently developed for the automotive industry. Due to their high strength and good formability, this group of steels is used in the automotive industry for complex and high strength parts. The microstructure of DP steel basically consists of a matrix of ferrite embed...

This work presents thermoplastic analysis of FG rotating disks with variable thickness and constant angular velocity. The solutions are obtained by variable material property (VMP) theory. In this theory, the domain is divided into some finite sub-domains in the radial direction, in which the properties are assumed to be constant and the form of th...